Determining When Heaving-To Is Dangerous

Member Steve asked an interesting question (edited for brevity).

My question is simple: Why would you ever consider stopping being hove to?

In a John Kretschmer book he was discussing this very point and said, “when heaving to is no longer an option” (loosely remembered). When is that? He did not elaborate at all.

The Pardey’s bridle system, they claim, provides sufficient drag to create a sufficient slick to provide sufficient stoppage of most (all?) breaking waves.

Even Hal Roth in his book, Handling Storms, also completely omits any comment on why someone would stop being hove to.

When the seas get big enough? When the breaking waves become more often? When the slick isn’t enough?

That’s a really good question. The problem is that I don’t know the answer, at least not for sure, and further no one does, as you have discovered in your research.

There are four fundamental problems here that make it impossible to answer your question definitively:

Storm Variable

First off, the mechanics of waves in a storm—height, frequency, and whether or not they are breaking—vary from storm to storm and are highly complex. So one sailor might heave-to for years without a problem and another be capsized by a huge breaking wave the very first time they try heaving-to.

Boat Variable

Second, while I believe that pretty much any boat can be made to heave-to, there is a very large spectrum across boats of how well they behave. So one crew may be perfectly safe in extreme weather hove-to and therefore conclude it’s a safe strategy, and another get rolled the first time they try it and therefore conclude that it’s a dangerous one. But in reality the two boats were lying very differently, so we can’t draw any conclusions.

Technique Variable

Third, heaving-to well requires that the boat have the right gear and that the crew have the skills and experience, first to get hove-to and then to assess whether or not the boat is lying safely. So even with identical boats we can’t be sure of the results.

For example, a crew could think they are hove-to, but in reality be fore-reaching too much to be safe—I have made exactly this mistake.

Observation Failure

Fourth, it’s impossible for even the most experienced crew to reliably gauge the state of the waves, and therefore the danger, or not, from the deck of a yacht at sea. This is not a guess on my part, but rather good science: Don Jordan’s research has shown that much of what we observe is illusionary and has little bearing on the actual wave dynamics at work.

And we don’t even have to rely on Jordan to understand this. The simple real-world proof of that unreliability of observation is that in almost every case when a boat gets capsized, the crew will state that just prior to disaster they were confident that the situation was under control.

Given these two points, the assertions made based on observation, even by the experienced, about what does and does not work at sea in a storm, are always suspect.

Or, to put it another way, in many cases the situation is far more dangerous than simple observation, even by old salts, seems to indicate.

Heaving-to Flawed?

So does all of that mean that I think that heaving-to is a dangerous technique? Not a bit of it. In fact, I’m fairly sure that the right boat in the right hands with the right gear—the Pardey-bridle or our own drogue-off-the-bow technique can help a lot—can survive most any storm, with the possible exception of a really bad wind-against-current situation.

But the problem with that last paragraph is the number of qualifications I was forced to use (four in all).

So we have come a full circle back to I just don’t know when heaving-to becomes dangerous, and further no one does, at least for sure.

What To Do?

So, given all that, what should we do? As usual, I can’t tell you what to do but I can say what our plan is.

We will continue to heave-to in gales because:

  • We are well set up for it.
  • We are experienced with the technique.
  • It’s an easier state to get in and out of than streaming a series drogue.

However, if there is any possibility of:

  • the weather increasing to storm force,
  • an ocean current against the wind,
  • a suddenly shelving bottom contour,
  • the storm or gale continuing for more than 24 hours with the resulting wave build;

we will bypass heaving-to and stream our Jordan Series Drogue™ (JSD). And further, if we have any doubts at all, we will stream the JSD.

Why the JSD?

Simply because the Jordan Series Drogue, and similar drogues based on Don Jordan’s work, are the only storm survival gear that:

  • Is based on good science rather than speculation and intrinsically flawed observation.
  • Has a near-perfect track record for survival in scores of truly horrendous storms across many different boat types and crew experience levels—it works in the real world and that trumps all speculation.

Summary

So, in summary, I can’t tell you how to gauge when heaving-to is dangerous, at least not for sure, but I can tell you that I have decided never again to put myself in a situation where I need to make that call by streaming a JSD well before it gets to that point.

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Meet the Author

John

John was born and brought up in Bermuda and started sailing as a child, racing locally and offshore before turning to cruising. He has sailed over 100,000 miles, most of it on his McCurdy & Rhodes 56, Morgan's Cloud, including eight ocean races to Bermuda, culminating in winning his class twice in the Newport Bermuda Race. He has skippered a series of voyages in the North Atlantic, the majority of which have been to the high latitudes. John has been helping others go voyaging by sharing his experience for twenty years, first in yachting magazines and, for the last 12 years, as co-editor/publisher of AAC.

44 comments … add one
  • Gerben Apr 22, 2017, 11:42 am

    Good write up and videos on JSD deployment in the Southern Ocean: http://freemansailing.com/2017/04/drogue-deployment-in-southern-ocean-gale/

    • John Apr 24, 2017, 7:48 am

      Hi Gerben,

      Yes, very good information and well worth putting 20 minutes aside for. Of course, as we now know when he did not deploy in time it ended badly, which is probably the most important lesson from Shane’s excellent site.

  • Drew Frye Apr 22, 2017, 3:07 pm

    Not for multihulls. This is a general statement, based on only a few boats–I’m sure there are exceptions–so just consider the concepts.

    The problem is three fold. First, a partial knock-down or severe heel, not uncommon when hove to in strong weather, is a capsize in a multihull. Second, the way cats avoid capsize when angling into the wind is by feathering, something you cannot do when hove to. Finally, most multihulls have a terrible, quick motion with the waves on the beam, even in moderate conditions. It’s just horrible when they are steep, impossible to stand and hard to hold on. But turn the stern to the waves and a glass of water will rest calmly on the salon table. It’s weird.

    As a result, as soon as it is no longer safe to slowly jog into the wind under deep reefs, it’s time to deploy a drogue or sea anchor. Because they are lighter and ride very well to these, it should be an easy decision. The light weight and wide beam also makes them easier to deploy and recover. Thus, the transition should be accomplished well before it gets scary wild. Because you will due this in moderate storms, it doesn’t always need to be a JSD, but as John and many others have pointed out, it may be difficult to change tactics later, so be very mindful.

    At least that has been my experience. No ballast = modified rules.

    • John Apr 22, 2017, 3:33 pm

      Hi Drew,

      I can certainly see what you are saying in connection with heaving-to and mulit-hulls.

      So I guess we are really on the same page: when in doubt deploy a JSD, multi or mono.

      • Drew Frye Apr 23, 2017, 5:59 pm

        To John, yes.

        To RDE, below, exactly. Some of those scare me a little, but that’s true in all categories of boats. Not all boats should cross oceans, and that does NOT make them bad boats, so long as the skipper understands the design. They may be the very best tool for the job. I had a Stiletto 27 (27 x 13 x 1300 pounds) that was the ultimate day sailor in many ways; very fast, take it to the beach, but ride out a squall if need be. Not a sea boat by any stretch… but I’m thinking about getting one again some day.

        My point is that the lack of ballast suggests different tactics. A multihull needs to use light weight and beam as an asset, not apologize for it, and the way to do that is by handling waves differently. Don’t try to do what the boat does not do well, but take advantage of what it does do well. This is seamanship. My last boat was 85% of the length, but only 15% of the weight and required quite different tactics. And yet, they are probably more similar to each other than to monohulls. A different way of thinking.

        • John Apr 24, 2017, 7:38 am

          Hi Drew,

          I couldn’t agree more. No point at all in having an offshore boat if one does not intend to go offshore. Here’s just one example of a boat that has some very cool features just because she is an inshore boat. https://www.morganscloud.com/2016/05/18/offshore-motorboats-and-an-ideal-geezer-boat/

          The worry comes for me when the marketing guys get involved and start making claims that the boat in question does not support.

  • RDE Apr 22, 2017, 11:45 pm

    Hi Drew,
    As you mentioned, not all multihulls are created equal.

    There is the generic condomaran:
    Heavy, with performance potential about the same as a monohull of the same length. Fixed long keels, low deck clearance, with sliding patio doors slightly above Home Depot grade to separate the cockpit from the boat interior.

    Vs. a catamaran designed for ocean voyaging:
    Overall beam at least 50% of the length. Narrow hull beam and entry angle to moderate pitching. Retractable daggerboards to enable the boat to adapt to beam-on waves rather than tripping on the keels, High bridge deck clearance. Stronger windows, and a watertight door system that will withstand a boarding sea.

    Kind of like comparing a Boreal to a Beneteau Sense 50. And the tactics for surviving a storm will be as different as that of the boat designs.

    • John Apr 23, 2017, 7:52 am

      Hi Richard,

      Makes sense. I think maybe the best storm survival tactic for the former type is stay in sheltered coastal waters.

      • Drew Frye Apr 24, 2017, 5:51 pm

        A personal (non) favorite of mine is the Gemini Legacy:
        https://3.bp.blogspot.com/-MGqD0Ov8hX4/UFzO0svo-aI/AAAAAAAAAcg/A0JxGVnjMi8/s640/DSCN0749.JPG

        No bridge deck clearance (this is a demo boat with empty tanks, no gear, and no dingy on the davits), only 2′ transom, and no door sill. It has only one winch and and 7 jammers feeding it. The designer told me it was for a “different kind of sailor.” Oh dear.

        It has replaced the Gemini 105Mc, which was a good coastal boat, given the value design compromises. The Legacy is a dock queen.

  • rene blei Apr 23, 2017, 6:51 pm

    Happy to say my really bad storm experience is limited, but the one time it did happen, while in an alloy monohull, the breakers came in from very different angles, no horizon and ofcourse that makes any survival tactic a bit of a challenge, but agree that a drogue is the best tactic to talk about it later.
    Best to stay will clear of it, if possible, but forecasting weather is still a mystery, with too many variables that still is not understood, making it impossible to predict longer-term.
    Rene

    • John Apr 24, 2017, 7:34 am

      Hi Rene,

      The interesting thing is that although many of us (including me) think that we have seen large waves coming from different angles, the science does not support that and so it’s probably one of those dangerous illusions that I talk about in the post. For more on this check out Don Jordan’s writing on the subject that I link to above.

  • Trevor Robertson Apr 23, 2017, 7:41 pm

    My comment applies to moderate or heavy displacement monohulls – I have no experience with multihulls or light displacement monohulls in heavy weather.

    I believe the protection afforded by the slick in the yacht’s lee while hove-to may be an illusion. The slick does exist and smooths the sea to a remarkable extent, but probably does little to moderate the rare large breaking waves that do the damage.

    The effect of the slick is an illusion of scale. If the size of the breaking tops of the waves are about one metre (which is considerable), the slick apparently halves their height. In fact what it really does is reduce the height of all seas by half a metre. It certainly does not halve the height of all seas. The actual numbers will vary, but I think it unlikely that the slick in the lee of a small vessel (less than 20 metres or so) when hove-to ever reduces the wave height by much more than a metre – and a metre reduction in the height of the rare but dangerous big breaking sea does little to reduce the damage it does.

    Another example of this illusion is the old one of spreading oil to calm waves. Tests by the RNLI in Britain about 50 years ago concluded that although oil has a remarkable calming effect on small waves, it has no appreciable effect on breaking waves that are large enough to be dangerous. I believe exactly the same applies to the slick a vessel produces when hove-to – both reduce the size of the small waves but not large breaking seas.

    That is not to say that there is no point in trying to keep the vessel in the slick while hove-to. It is more comfortable than fore reaching ahead of the slick or drifting behind it. I have ridden out quite a few near gales and gales (force 7 and 8) comfortably hove-to in Iron Bark’s own slick. I remember one in the North Atlantic where the calming effect was sufficient for me to sit in the cockpit and watch the fulmars paddling in the slick, but we both had to jump for shelter from the odd bigger breaker.

    With a bit of fiddling around, most boats can be induced to make a square drift and lie in their own slick – some will need some sort of a drag device off the bow, a few particularly lively or small vessels will need to add a spring line to the drogue to adjust the angle that they lie to the seas (the Pardy system). Some such as my Iron Bark will lie-to under deep-reefed mainsail alone or main and backed staysail and can be kept in the slick by adjusting the sheets and how far the helm is lashed down.

    A vessel that can heave-to without drogues off the bow will find it easier to adjust things so she fore reaches a little or drifts slowly downwind, allowing it to avoid a danger to leeward (land, ice etc). This will of course be a more uncomfortable as the vessel will no longer be in the slick.

    Like John, I do not know when it is no longer safe to heave-to even on my own boat, which I know well. I could not (and would not) try to give firm rules applicable to all vessels – that is way beyond my ability. I think that when in doubt, the safest option is probably to run off with some sort of drogue astern and it is better to do this too soon than too late – which of course is exactly John’s advice.

    Regards
    Trevor

    • John Apr 24, 2017, 7:46 am

      Hi Trevor,

      Yes, the whole slick thing is an interesting one and, like you, I tend to be a bit sceptical about how it will work in breaking waves.

      On the other hand, the Pardeys do make convincing case and have ridden out some pretty bad stuff heaved to with and without a drag device. Also, I do have to admit that in the blow I wrote up (linked to above) we got hit hard by a breaking wave twice when we were forereaching out of our slick and not at all after we deployed the Galerider off the bow and stayed behind the slick.

      Anyway, like you, in the end I come down on the side of “who the hell wants to fine out the hard way that slicks don’t work” side of the argument.

  • Ernest Apr 24, 2017, 12:08 pm

    Does anyone know of a report where a vessel that has been heaved-to correctly (within its slick path) was capsized by a breaking wave?

    • John Apr 25, 2017, 6:47 am

      Hi Ernest,

      No, I don’t, or at least not for sure, but the problem, as is so often the case, is that there is no really good scientific data collection in offshore sailing. And this goes double when dealing with storm conditions where observations from the deck of a yacht by a tired and probably sea-sick crew are inherently subjective.

      Therefor I fall back on what we do know for sure and that is that the JSD has a very good track record of keeping boats safe in terrible conditions.

      All that said, if you would like to investigate heaving-to further, I strongly recommend Lin and Larry Pardey’s book on heavy weather tactics.

      • Ernest Apr 25, 2017, 7:09 am

        I already digested the Pardley “bible” and it absolutely made me believe in their heave-to tactics. On the other hand I feel that using a JSD you’re more manoeverable and could still find your way out of a system, given you’re not in the wrong corner (NE quadrant in the northern hemisphere). Its not an easy decision, but I feel once hove-to you’re stuck with it as it might be impossible to get the boat moving again fast enough to avoid a dangerous situation.
        What do you think – would Shanes’ boat have lived being ove-to? Obviously a third deployment of a JSD had helped.

        • John Apr 26, 2017, 9:06 am

          Hi Ernest,

          Hi Ernest,

          While I agree that getting out of the Pardey Bridle set up will take a while, but I have found getting in and out of being heaved to very quick and easy particularly if we start the engine for a bit of extra manoeuvrability. And retrieving our Galerider when set in our off the bow technique is far easier than getting a JSD back. (I’m not advocating heaving-to here, just sharing my experience).

          As to whether of not Shane would have been OK, I’m simply not going to speculate because, for the reasons detailed in the post above, I would just be guessing.

          What we do know is that he did well with a JSD twice before and to me that’s what matters.

      • Ernest Apr 25, 2017, 7:11 am

        And on the other hand John Kretschmer favorizes forward reaching to get out of the system, not deploying anything at all (currently reading his excellent book “Sailing a Serious Ocean”)

        • John Apr 26, 2017, 9:17 am

          Hi Ernest,

          Yes, fore-reaching the way John does it has a good record, although not (I think) as good as the JSD. However, John’s technique has one huge problem: safety depends on skillful steering (and everything holding together) and without a large, strong, and well rested crew, that does not work.

          More here: https://www.morganscloud.com/2013/06/01/heavy-weather-strategy-goals/

          I can attest from my own experience with surviving a bad storm in the Gulf Stream (wind against current) in my old boat by fore-reaching that steering well for more than about 45 minutes was beyond any of us and we were six: young, experienced and fairly fit.

          More here: https://www.morganscloud.com/2013/06/01/survival-storms/

      • RDE Apr 25, 2017, 10:03 am

        I met the Pardeys soon after they had made a 54 day crossing from Japan on their 24′ Serafin. Asked them what their secret for getting along together on such a long voyage on such a small boat. “Lot’s of box wine.”

        A few years later I was out bay sailing with a group of people on an exact replica of their boat. A gust came through and the inexperienced person at the helm managed to put the spreaders in the water. A rather strange design, broad stern, narrow bow entry, huge bowsprit. I’ve all the admiration in the world for the seamanship of anyone who could complete the voyages they have in that kind of boat.

        • John Apr 26, 2017, 9:33 am

          Hi Richard,

          So true, it’s 90% seamanship and 10% boat.

    • Richard Hudson Apr 25, 2017, 12:09 pm

      Hi John,

      I think you’ve written an excellent analysis of the difficulties with determining when heaving-to is no longer safe, and developed very useful guidelines for making that decision.

      Fifteen years ago, when I was much more impressed by claims of the safety of heaving-to, I rolled over while hove-to ( http://www.issuma.com/rhudson/orbitlog/OrbitsLastVoyage.htm ). It was a painful lesson.

      Your experience of suddenly being hit hard by a breaking wave while hove-to ( https://www.morganscloud.com/2013/06/01/when-heaving-to-is-dangerous/ ) sounds somewhat similar, but that you had a larger boat, weren’t near a suddenly shelving bottom contour, and you were able to observe the situation and figure out the problem in half an hour, whereas I had rolled over very soon after the first indication of a problem.

      Hi Ernest,
      I think my story above is one of a “vessel that has been heaved-to correctly (within its slick path)” that was capsized by a breaking wave. Except that when the wave hit, I was not on deck to be able to see that my boat was still hove-to in it’s slick. Before then, I had spent a lot of time on deck, confirming the boat was hove-to in it’s slick.

      Richard

      • Ernest Apr 25, 2017, 12:33 pm

        Good god, THATs a story. Thanks for sharing!

      • John Apr 26, 2017, 8:53 am

        Hi Richard,

        That is quite a story and well told too. I also read your technical notes, which I though eminently well thought out, particularly in that you were clear about all the uncertainties in an accident like this.

        To me there is much to learn from your experience, but three things stand out particularly.

        • Everything changes when a storm occurs in shallow water and that goes double if the contour shelves quickly.
        • With a situation like that, the boats stability does not make a blind bit of difference.
        • There is no such thing as a roll proofed boat. Once a full 360 has happened the damage and injuries will almost always require abandonment.

        Interestingly, I have been in the same piece of ocean in heavy weather—1997 on a passage from Reykjavik to Scotland in early September—and can confirm that it can be a very nasty place indeed.

        I strongly recommend a careful read of David’s excellent account and technical notes to all.

        • Richard Hudson Apr 26, 2017, 10:32 am

          Hi John,

          Thanks very much, I agree with all your points.

          > Everything changes when a storm occurs in shallow water and that goes double if the contour shelves quickly

          I thought a lot about this going into the storm–being near a place where the depth went from 1500m to 500m. I thought, is 500m shallow?, and is that change in depth steep? 500m seemed pretty deep…

          Nowadays, if it’s forecast to be windy (say, Force 7 or more), I’m thinking about the possibility of big, steep waves if I see the bottom going from 3000m to 2000m. But those numbers are just a guess on my part (I haven’t actually spent a great deal of time in Force 7 and above, observing what happens in what depths).

          We know that shallow water or steeply sloping bottoms can result in dangerous waves. But I still don’t know a good way of determining what is ‘shallow’, and what is a ‘steeply sloping bottom’. If you, or anyone else, has any good rules-of-thumb or formulas for determining what is ‘shallow’ or what is ‘steeply sloping’, I’d be interested to learn.

          Richard

          • John Apr 27, 2017, 8:07 am

            Hi Richard,

            Yes, hard to define. The only rule I have ever heard is the old “beware the 100 fathom line”.

            That said, my guess is that since it was so deep, what got you was not the depth contour change per se but rather the effect of that contour change on the ocean currents in the area.

            I have often noticed during my many crossings from the North American east coast to and from Bermuda that there is a noticeable change in the wave state, even in quite benign weather, when we cross the edge of the continental shelf, even though the water is still far too deep to actually be felt by surface waves. My thinking is that said edge of the shelf causes any currents to change direction and perhaps accelerate and that in turn causes the change in wave state.

      • Matthieu Apr 30, 2017, 10:08 am

        Hi Richard,
        Thank you so much for sharing your painful story on Orbit, in particular your technical notes section: plenty of useful information and potential lessons/preparation tips for the rest of us in there. Really appreciate it.

  • Rene Apr 24, 2017, 2:15 pm

    Thanks John for your comment on wave directions.
    In a force 8 everything still appears to be “orderly”, but that appears to change to chaotic as the storm intensified. When cocooned in a small space, your mind could well play tricks on you, but whatever it was, it sure got me praying. Maybe not unlike to that bad dude and slave trader by the name of John Newton, who prayed when caught in a bad storm and years later wrote ” Amazing Grace”. No, don’t panic, I’m not a poet 🙂

  • Ann Apr 24, 2017, 3:10 pm

    Thank you for a thought provoking article. I wondered if any of your readers have had any experience with or advice for us yawl owners in terms of sail configuration.
    Thanks!

    • John Apr 25, 2017, 6:55 am

      Hi Ann,

      I haven’t sailed yawls much—I have a lot of ketch time, but never in a really big blow—so I don’t have any first hand information. I believe that some people advocate heaving-to under mizzen and storm jib but given that most mizzen masts are fairly lightly rigged I’m not sure I would not just treat the boat as a sloop and be done with it. That said, only experimentation, first in relatively easy weather and then slowly escalating, will tell you for sure.

      We have some thoughts on heaving-to here that may help: https://www.morganscloud.com/2013/06/01/how-to-heave-to-in-a-sailboat/

      • Ann Apr 25, 2017, 10:43 am

        Hi John, thanks for your reply. Having had limited experience here, I nonetheless am inclined to agree with you re the mizzen. I am having an inner forestay put on my boat this spring so I can use a staysail. I see you have a roller furling one. I was not not conrtemplating that. Any other suggestions as this is being done would be greatly appreciated.

  • Rob Gill Apr 24, 2017, 5:19 pm

    Hi John,
    In terms of “when”, for those of us yet to experience real heavy weather conditions offshore with possible breaking waves (and hope not to), any time with less than 4 hours of daylight left to balance the boat and sail plan, rig a bow drogue if needed and check we are staying within the slick would seem to be dangerous. Without daylight to make these adjustments the JSD would appear to be more prudent.
    best regards
    Rob

    • John Apr 25, 2017, 6:31 am

      Hi Rob,

      Yes, I think that’s another good variable to crank into the mix, particularly if the crew has not hove-to often.

  • Richard Dykiel Apr 25, 2017, 1:32 pm

    Reading all these comments from experienced people the conclusion I’m drawing is: heave to, and then when conditions worsen, deploy JSD. I wouldn’t try the intermediate step of deploying anything from the bow when heaving to, because it would be irretrievable in worsening conditions.

    • John Apr 26, 2017, 9:29 am

      Hi Richard,

      See my comment above to Ernest on retrieval.

      • Richard Dykiel Apr 26, 2017, 1:02 pm

        Yes but using the engine, and perhaps still need a trip to the bow? If your boat is equipped with a JSD what is the use of laying hove to under galerider or sea anchor? Avoid running into a lee shore?

        • John Apr 26, 2017, 4:07 pm

          Hi Richard,

          Because heaving-to is a lot easier and quicker to get in and out of than using a JSD. See the post above for more on that and when I would, or would not, heave-to.

          • Richard Dykiel Apr 26, 2017, 4:57 pm

            Pardon if there is a misunderstanding, but my question was about: if you started hove to (I agree it’s easier to get in and out), BUT the conditions worsen, is it worth trying step #2 (drogue off the bow) or better to go direct to step #3 (JSD). My conclusions were that step #2 was an unnecessary complication.

          • John Apr 27, 2017, 8:09 am

            Hi Richard,

            Ah, I see. On a general basis I think you are right, just go to the JSD. This fits with my rule above: when in doubt go with the JSD.

  • Ernest Apr 28, 2017, 4:10 pm

    Just another question: when switching from heave-to to JSD running, would you
    – start running first, and deploy the JSD when the boat is already moving, or
    – first deploy the JSD over the staern while the boat is “parked”, and start running “intop the drogue” then?
    I would favor the second method as there is less movement in the boat, no drag on the partially deployed droge which may prove helpful to avoid deployment problems, such as a line being tangled somewhere on deck, or around the wind vane (as it had almost happened to Shane)

  • Chuck B May 11, 2017, 12:58 pm

    Here is a fantastic paper on the simulation of effects of hull and keel on wave shape and behavior when hove to: http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.977.2267&rep=rep1&type=pdf

    The author doesn’t get into breaking waves, but it is a great start.

    Chuck

    • John May 12, 2017, 8:40 am

      Hi Chuck,

      Thanks, I took a quick look and, although the math is way beyond my pay grade, it does seem to show pretty conclusively that the slick to windward of a hove-to boat does have a substantial effect, which is comforting.

      That said, I think we must be very careful not to read too much into this report since, as you point out, it does not model breaking waves. And, as Don Jordan and the Wolfson Unit showed pretty conclusively, it is breaking waves that cause boats to be rolled.

      So, given that, while it is interesting, I would not change anything I have written in the post above based on the report.

      • Chuck B May 12, 2017, 11:33 am

        Agreed John – I’m just finding it encouraging (even inspiring!) that there’s interest in applying rigor to the study of this even in Mr. Jordan’s absence. Hopefully the results and questions raised by this work will lead to additional study involving breaking waves.

        Best,
        Chuck

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